package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;


import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill_tea.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }




    private static final ExecutorService SEKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init() {
        SEKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }


    public class VoucherOrderHandler implements Runnable {
        String queueName = "stream.orders";
        @Override
        public void run() {
            while (true) {
                try {
                    // 1.获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    // 2.判断订单信息是否为空
                    if (list == null || list.isEmpty()) {
                        // 如果为null，说明没有消息，继续下一次循环
                        continue;
                    }
                    // 解析数据
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    // 3.创建订单
                    createVoucherOrder(voucherOrder);
                    // 4.确认消息 XACK
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    handlePendingList();
                }
            }
        }
        private void handlePendingList() {
            while (true) {
                try {
                    // 1.获取pending-list中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    // 2.判断订单信息是否为空
                    if (list == null || list.isEmpty()) {
                        // 如果为null，说明没有异常消息，结束循环
                        break;
                    }
                    // 解析数据
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    // 3.创建订单
                    createVoucherOrder(voucherOrder);
                    // 4.确认消息 XACK
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                }
            }
        }
    }
//    private  BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
//    public class VoucherOrderHandler implements Runnable {
//        @Override
//        public void run() {
//            while (true){
//                try {
//                    //1.读取队列中的订单信息
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    //2.创建订单
//                    handleVoucherOrder(voucherOrder);
//                } catch (Exception e) {
//                    log.error("处理订单异常",e);
//                }
//            }
//        }
//    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        //1创建锁对象
        //SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        RLock lock = redissonClient.getLock("order:" + userId);
        //2获取锁
        boolean isLock = lock.tryLock();
        //3判断是否获取锁成功
        if (!isLock) {
            //获取锁失败，直接返回失败或者重试
            log.error("不允许重复下单");
            return;
        }
        try {
            //8.返回订单id
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }
    private  IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisIdWorker.nextId("order");
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString(),
                String.valueOf(orderId)
        );
        //2.判断结果是否为零
        int r = result.intValue();
        if (r!=0){
            //2.1 不为0,没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //2.2 为0，有购买资格，实现下单逻辑
        //获取代理对象（事务）
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //4.返回订单id
        return Result.ok(orderId);
    }
    /**
    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString()
        );
        //2.判断结果是否为零
        int r = result.intValue();
        if (r!=0){
            //2.1 不为0,没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //2.2 为0，有购买资格，实现下单逻辑
        long orderId = redisIdWorker.nextId("order");
        //TODO 保存阻塞队列
        // 3.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        // 3.1.订单id
        voucherOrder.setId(orderId);
        // 3.2.用户id
        voucherOrder.setUserId(userId);
        // 3.3.代金券id
        voucherOrder.setVoucherId(voucherId);
        //3.4放入阻塞队列
        orderTasks.add(voucherOrder);
        //获取代理对象（事务）
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //4.返回订单id
        return Result.ok(orderId);
    }*/
    /*
    @Override
    public Result seckillVoucher(Long voucherId) {
        //1.查询优惠券
        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
        Integer stock = seckillVoucher.getStock();


        if (seckillVoucher == null){
            //优惠券不存在
            return Result.fail("优惠券不存在");
        }
        //2.判断秒杀是否开始
        if (seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())) {
            //尚未开始
            return Result.fail("秒杀尚未开始");
        }
        //3.判断秒杀是否结束
        if (seckillVoucher.getEndTime().isBefore(LocalDateTime.now())) {
            //已经结束
            return Result.fail("秒杀已经结束");
        }
        //4.判断库存是否充足
        if (stock < 1) {
            //库存不足
            return Result.fail("库存不足");
        }
        Long userId = UserHolder.getUser().getId();
        //创建锁对象
        //SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        RLock lock = redissonClient.getLock("order:" + userId);
        //获取锁
        boolean isLock = lock.tryLock();
        //判断是否获取锁成功
        if (!isLock) {
            //获取锁失败，直接返回失败或者重试
            return Result.fail("不允许重复下单");
        }
        try {
            //获取代理对象（事务）
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            //8.返回订单id
            return proxy.createVoucherOrder(voucherId);
        } finally {
            lock.unlock();
        }
    }
    */

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //5.一人一单
        Long userId = voucherOrder.getUserId();
        // 5.1.查询订单
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        // 5.2.判断是否存在
        if (count > 0) {
            // 用户已经购买过了
            log.error("用户已经购买过一次！");
            return ;
        }
        // 6.扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1") // set stock = stock - 1
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0) // where id = ? and stock > 0
                .update();
        if (!success) {
            // 扣减失败
            log.error("库存不足！");
            return;
        }
//        // 7.创建订单
//        VoucherOrder voucherOrder = new VoucherOrder();
//        // 7.1.订单id
//        long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        // 7.2.用户id
//        voucherOrder.setUserId(userId);
//        // 7.3.代金券id
//        voucherOrder.setVoucherId(voucherOrder);
        save(voucherOrder);

//        // 7.返回订单id
//        return Result.ok(orderId);
    }
}
